为确定减压-超声波辅助醇提法提取薇菜黄酮的最佳工艺条件，以黄酮提取量为指标，采用响应面法对主要工艺参数进行优化。方差分析结果表明：回归模型较好地反应了薇菜黄酮提取量与料液比、乙醇体积分数和超声温度的关系；最佳工艺条件为：料液比1:60，乙醇体积分数49.97%，超声温度70.19 ℃，超声时间70 min，超声功率300 W，提取压力0.08~-0.1 MPa。此条件下薇菜黄酮提取量为（118.924±1.950）mg/g。回归模型的失拟值不显著，说明该回归模型模拟较好。通过体外抗氧化试验表明：减压-超声法和常压超声法提取黄酮类物质对DPPH自由基的IC50分别为0.117 mg/mL和0.119 mg/mL；对ABTS自由基的IC50分别为0.072 mg/mL和0.076 mg/mL；总还原能力由强到弱为：减压-超声法>常压超声法>水溶Vc。结论：相同提取条件下减压-超声提取法的黄酮提取量比常压超声提取法黄酮提取量增加（20.01±1.64）mg/g，且不破坏黄酮类化合物抗氧化活性。

In order to determine the optimum conditions of ultrasound-assisted decompression of alcoholic extraction of flavonoid from Osmunda japonica Thunb, the main process parameters were optimized by response surface methodology (RSM) with flavonoid extraction as an indicator. The results of variance analysis showed that the regression model could well reflect the relationship between extraction volume of flavonoids and the ratio of solid to liquid, the volume fraction of ethanol and the temperature of ultrasonic.The optimum extraction processing parameter was ascertained as follows: the solid-liquid ratio 1: 60, the volume fraction of alcohol 49.97%, ultrasonic temperature 70.19℃, ultrasonic time 70 min, ultrasonic power 300 W, and extraction pressure 0.08~-0.1 MPa. Under these conditions, the yield of flavonoids extracted from Osmunda japonica Thunb was (118.924 ± 1.950) mg/g. Antioxidant test results showed that: the IC50 of flavonoids extracted from Osmunda japonica Thunb by decompression-ultrasonic and atmospheric pressure ultrasonic extraction for 1,1-diphenyl-2-picrylhydrazyl (DPPH) were 0.117 and 0.119, respectively. The IC50 of 2,2‘-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid)(ABTS+) were 0.072 and 0.076, respectively. The total reducing power: decompression- ultrasonic > atmospheric pressure ultrasonic > Vc. Under the same extraction conditions, the extraction of flavonoids by decompression-ultrasonic extraction method was 20.01 ± 1.64 mg/g higher than that by ultrasonic extraction, and the antioxidant activity of flavonoids was not affected.

“十三五”国家重点研发计划项目（2016YFC0500307-07）